docs: def _parse_CHANLIMIT(value):
          """
          >>> res = FeatureSet._parse_CHANLIMIT('ibe:250,xyz:100')
          >>> len(res)
          6
          >>> res['x']
          100
          >>> res['i'] == res['b'] == res['e'] == 250
          True
          """
          pairs = map(string_int_pair, value.split(','))
          return dict(
              (target, number)
              for target_keys, number in pairs
              for target in target_keys
          )